Green synthesis and characterization of magnetite (Fe3O4) nanoparticles using Chromolaena odorata root extract for smart nanocomposite

Abstract We report a facile and green biosynthetic co-precipitation of magnetite nanoparticles using extract from the root of Chromolaena odorata. The particle sizes are in the range 5.6–16.8 nm. Absorption band edges of the particles at 205 nm and 291 nm are ascribed to surface plasmon vibrations, and estimated band gap energy of the particle is 1.97 eV. The basified extract produced 30-fold mono-phased magnetite nanoparticles with reduced band gap in comparison to bare magnetite nanoparticles. Basification of the plant extract inhibited the co-precipitation of other cations in solution; promoting the formation of water dispersible hydrophilic nanoparticles.